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Constraints on the emission region of 3C 279 during strong flares in 2014 and 2015 through VHE γ-ray observations with H.E.S.S.
(EDP Sciences, 2019)
The flat spectrum radio quasar 3C 279 is known to exhibit pronounced variability in the high-energy (100 MeV < E < 100 GeV) γ-ray band, which is continuously monitored with Fermi-LAT. During two periods of high activity ...
Discovery of TeV y-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift
(EDP Sciences, 2013)
Very high-energy γ-ray emission from PKS 0447−439 was detected with the H.E.S.S. Cherenkov telescope array in December 2009. This blazar is one of the brightest extragalactic objects in the Fermi bright source list and has ...
Discovery of very high energy γ-ray emission from the BL Lacertae object PKS 0301-243 with H.E.S.S.
(EDP Sciences, 2013)
The active galactic nucleus PKS 0301−243 (z = 0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV < E < 100 GeV) by Fermi/LAT. This paper reports on the discovery of PKS 0301−243 ...
PKS 2005-489 at VHE: four years of monitoring with HESS and simultaneous multi-wavelength observations
(EDP Sciences, 2010)
Aims. Our aim is to study the very high energy (VHE; E>100 GeV) γ-ray emission from BL Lac objects and the evolution in time of their broad-band spectral energy distribution (SED).
Methods. VHE observations of the ...
Simultaneous multiwavelength observations of the second exceptional y-ray flare of PKS 2155-304 in July 2006
(EDP Sciences, 2009)
Aims. The X-ray-TeV connection and the evolution of the emitting particle population is studied in high-energy peaked BL Lac objects, by obtaining spectral information in both bands on sub-hour timescales.
Methods. ...
The 2010 very high energy γ-ray flare and 10 years of multi-wavelength observations of M 87
(IOP Publishing, 2012)
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray ...
Upper limits from HESS active galactic nuclei observations in 2005-2007
(EDP Sciences, 2008)
Aims.Very high energy (VHE; GeV) γ-ray studies were performed for 18 active galactic nuclei (AGN) from a variety of AGN classes.
Methods.VHE observations of a sample of 14 AGN, considered candidate VHE emitters, were ...
Discovery of VHE gamma-rays from the high-frequency-peaked BL Lacertae object RGB J0152+017
(EDP Sciences, 2008)
Aims. The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; >100 GeV) $\gamma$-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by ...
Multi-wavelength observations of H 2356-309
(EDP Sciences, 2010)
Aims. The properties of the broad-band emission from the high-frequency peaked BL Lac H 2356–309 (z = 0.165) are investigated.
Methods. Very high energy (VHE; E > 100 GeV) observations of H 2356–309 were performed with ...
A multiwavelength view of the flaring state of PKS 2155-304 in 2006
(EDP Sciences, 2012)
Context: Multiwavelength (MWL) observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies (VHE, E ≳ 100 GeV) occurred, provide a detailed ...